Herbicidal compounds and methods

ABSTRACT

A NOVEL CLASS OF COMPOUNDS COMPRISING THE ESTERS OF 2-(W,W-DIETHYLENEIXYURAMIDO) BENZOIC ACID AND THE THIO ANALOGUES THEREOF ARE PROVIDED. THE COMPOUNDS ARE USEFUL AS HERBICIDES AND ARE ESPECIALLY USEFUL FOR CONTROLLING WILD OATS IN THE PRESENCE OF DESIRABLE CROPS.

United States Patent Olfiee 3,757,016 Patented Sept. 4, 1973 US. Cl. 260-2412 B 11 Claims ABSTRACT OF THE DISCLOSURE A novel class of compounds comprising the esters of 2-(w,w-diethyleneoxyuramido)benzoic acid and the thio analogues thereof are provided. The compounds are useful as herbicides and are especially useful for controlling wild oats in the presence of desirable crops.

This application is a continuation-in-part of our copending application Ser. No. 833,870 filed June 4, 1969, now abandoned, which in turn is a continuation of our application Ser. No. 598,981 filed Dec. 5, 1966, now abandoned, which in turn is a continuation-in-part of our application Ser. No. 524,452 filed Feb. 2, 1966, and now abandoned.

This invention relates to novel uramidobenzoate compounds and herbicidal compositions and methods utilizing said uramidobenzoates.

According to the present invention there are provided novel compounds of the formula COOR X ll NH -N Y where R is selected from the group consisting of alkyl, alkenyl, alkynyl, and aryl, and X and Y are each selected from the group consisting of oxygen and sulfur. The organic groups represented by R can also have halogen substituents, such as chloro, bromo, and fluoro.

Thus, the invention provides, as novel compounds, the esters of 2-(w,w-diethyleneoxyuramido)benzoic acid and its thio analogues. The w,w-diethyleneoxyuramido moiety can also be named morpholinocarbonylamino and the two terms can be used interchangeably herein. Preferred esters are the lower alkyl, lower alkenyl, lower alkynyl groups of 1 to about 8 carbon atoms which can also have halogen substituents and the monocyclic aryl groups such as phenyl, alkylphenyl, and the halophenyl groups. Typical ester groups represented by R are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, n-hexyl, allyl, Z-propynyl, 2- butenyl, l-methyl-Z-propenyl, 2-chloroethyl, 4-chloro-2- butynyl, n-octyl, 2-chloro-2-propenyl, 4-brorno-2-butynyl, trifluoroethyl, trichloroethyl, phenyl, 2,4-dichlorophenyl, 4-methylphenyl, and the like.

The compounds of the present invention are normally crystalline solids or viscous oils which are soluble in organic solvents such as alcohols, benzene, and xylene. The salts are generally soluble in water. The compounds are readily prepared from the corresponding esters of anthranilic acid and morpholine by either of two methods. According to one method of preparation, the anthranilate is converted to the corresponding isocyanate or isothiocyanate and then reacted with morpholine to give the desired compound. Alternatively, morpholine is converted to the carbamyl chloride derivative and then reacted with the anthranilate to give the desired compound. Thiomorpho-line can also be used in the preparations to obtain the thio analogues.

The methods of preparation can be illustrated by the following equations in which X and Y have the significance previously assigned and R is an organic group, preferably lower alkyl.

X NH-ti-N Y In the reaction illustrated by Equation A, the anthra nilate, preferably as the hydrochloride, is reacted with phosgene or thiophosgene to give the isocyanate or isothiocyanate. This reaction takes place in a relatively high boiling solvent, such as chloroform, toluene, xylene, isooctane, or the like. The resultant isocyanate or isothiocyanate is isolated by distillation and then reacted with morpholine or thiomorpholine in the presence of an inert solvent, such as the hydrocarbons, to give the desired uramidobenzoate.

Referring now to Equation B, morpholine or thiomorpholine is reacted with phosgene or thiophosgene to give the carbamyl chloride which is then reacted with the anthranilate to provide the desired uramidobenzoate. Preferably, an inert solvent is employed as in the reactions illustrated by Equation A.

The desired uramidobenzoate is isolated and purified by conventional procedures such as by recrystallization from a suitable solvent as, for example, alcohol-water mixtures.

The higher esters can also be prepared by well-known transesterification procedures with the lower esters, especially the methyl ester.

The following examples are presented to illustrate the preparation of typical compounds of the invention but the invention is not to be considered restricted to the specific examples given.

EXAMPLE I Methyl 2-isocyanatobenzoate tube, stirrer and a reflux condenser connected to a water scrubber, was added 200 grams (1.32 moles) of methyl anthranilate dissolved in three liters of isooctane (commercial grade). Dry hydrogen chloride was passed into the isooctane solution of methyl anthranilate for 7 hours and a thick white precipitate was formed. The mixture was refluxed and phosgene was passed in at a rapid rate for 7 hours. The reaction mixture was then cooled and the insoluble precipitate was removed by filtration. The isooctane was removed at reduced pressure and the remaining residue was distilled to give 178.4 grams (76.2%) of product, B.P. 146 C./ 16 mm.

3 Methyl 2-(w,w-diethyleneoxyuramido)benzoate-.

A solution of 30.8 grams (0.353 mole) of morpholine in ml. of benzene was added dropwise to a solution of 62.6 grams (0.353 mole) of methyl 2-isocyanatobenzoate in 200 ml. of benzene. The reaction mixture'was refluxed for 1.25 hours and then concentrated under-reduced pressure until the residue solidified. The solid'prodnot was suspended in a warm pentane-ether mixture, collected by filtration, washed with pentane and dried under vacuum. The product, 88.1 grams (94%), melted at 108 109 C. After recrystallization from an ethanol-water mixture, the purified product melts at 100-112 C.

Analysis.Calculated for C H N O (percent): C, 59.08; H, 6.10; N, 10.60. Found (percent): C, 59.06; H, 6.15; N, 10.53.

EXAMPLE II .Was'dissolved in 30 ml..of dry hexane with slight Warming and 4.56 grams (0.052 mole) of morpholine was added slowly. The reaction was exothermic and the mixture was mediately. The. solid product was recrystallized from ethastirred for a few minutes after addition was completed.

The solid product was removed by filtration and recrystallized from ethanol; M.P. 1l7-119 C.; yield 10.8 grams (75% Analysis-Calculated for C H N O (percent): C, 60.41; H, 6.51; N, 10.06. Found (percent): C, 60.32; H, 6.63; N, 10.14.

EXAMPLE III n-Propyl 2- (w,w-diethyleneoxyuramido benzoate EXAMPLE IV n-Butyl 2-(w,w-diethyleneoxyuramido)benzoate Morpholine (4.0 grams; 0.0457 mole) was added slow- 1101 and melted at 106-110 C. After recrystallization from hexane, the product melted at 116l17.5 C.

Analysis.Calculated for C H N O S (percent): C, 55.70; H, 5.75; N, 9.99. Found (percent): C, 55.84; H, 6.14;. N,-9.63.

. EXAMPLE VI Morpholinylcarbonyl chloride Phosgene (108 ml.) was added to one liter of stirred xylene at 0 5 C.- To this cold solution was slowlyadded a solution of 174.2 grams (2.0 moles) of morpholine in 200ml. of xylene. The resultant mixture was stirred for one hour while cooled with an ice bath and then heated on a steam bath. The insoluble solid was separated by filtration and the filtrate was concentrated. The residual liquid was distilled at 124-127 C./20 mm. to give 112.55 grams (75%) of product; n 1.4985 (21 C.).

sec-Butyl 2-(w,w-diethyleneoxyuramido)benzoate To a solution of 9.66 grams of (0.05 mole) of sec-butyl anthranilate and 3.96'grams (0.05 mole) of pyridine in 50ml. of benzene'was added a solution of 7.48 grams (0.05 mole) of morpholinylcarbonyl chloride in 50 ml. of benzene. The reaction mixture was refluxed for 30 hours, cooled and the insoluble solid was filtered. The benzene solution was washed with water, the organic layer dried over anhydrous magnesium sulfate and then concentrated to a viscous oil. The residual oil was distilled at 190 C./ 0.4 mm. and 1.5 grams of product was obtained: n 1.5539 (20 C.).

Analysis.-Calculated for C H N O (percent): C, 62.72; H, 7.23; N, 9.14. Found (percent): C, 63.00; H, 7.36; N, 9.16.

EXAMPLE VII Isopropyl 2-(w,w-diethyleneoxyuramido)benzoate A solution of 7.48 grams (0.05 mole) of morpholinylcarbonyl chloride in 50 ml. of benzene was added to a C, 61.60; H, g

ly to a solution of 10.0 grams (0.0457 mole) of 'butyl 2-isocyanatobenzoate in 30 ml. of hexane. The reaction was exothermic. The mixture was refluxed for 16 hours and the cloudy solution then cooled. The insoluble product was separated by filtration and washed with pentane. A total of 13.3 grams (95%) of product melting at 59.5 66 C. was isolated. The pure product melted at 67- 67.5 C. after recrystallization from ethanol. 7

Analysis.-Calculated for C H N O (percent): C, 62.73; H, 7.24; N, 9.15. Found (percent): C, 62.92;H, 7.13; N, 9.10.

EXAMPLE V Methyl 2-isothiocyanatobenzoate A solution of 15.1 grams (0.1 mole) of methyl anthranilate in 25 ml. of chloroform was added slowly to a solution of 13.6 grams (0.118 mole) of thiophosgene in 25 ml. of chloroform and the mixture was then refluxed for 4 hours. Chloroform and excess thiophosgene was removed by distillation and the residual liquid was distilled at 9192 C./0.15 mm. to give 16.8 grams (87%)"of product.

Methyl 2-(w,w-diethyleneoxythiouramido)b enzoate, 4 A solution of 2.2 grams (0.025 mole) of morpholine in 10 ml. of hexane was added to a stirred solution of 4.8 0

grams 0.025 mole) of methyl 2-isothiocyanatobenzoate in 30 ml. of hexane. The reaction mixture solidified imsolution of 8.96 grams (0.05 mole) of isopropyl anthranilate and 3.96 grams (0.05 mole) of pyridine in 50 ml. of benzene. The mixture was refluxed for 30 hours and the benzene solvent was then removed by distillation under reduced pressure. The solid residue was dissolved in Water and the insoluble oil was extracted with ethyl ether. The ethereal extract was dried over anhydrous magnesium sulfate and then concentrated under reduced pressure to an oil. The residual oil was distilled at C./0.1 mm. and 3.7 grams of amber-colored, viscous oil was obtained; n 1.5535 (23 C.).

.Analysis.Calculated for C H N O (percent): C, 61.62; H, 6.89; N, 9.58. Found (percent): C, 62.37; H, 6.95; N, 9.75.

' EXAMPLE VIII Allyl 2- (w,w-diethyleneoxyuramido benzoate EXAMPLE IX Methyl 2- (w,w-diethylenethiouramido) benzoate A 200 mL'rOund-bottOmed flask equipped with a reflux condenser: and magnetic stirrer was charged with 2.00 grams (0.019 mole) of thiomorpholine (prepared by reduction of 3-thiomorpholineone with lithium aluminumhydride), 3,43 grams (0.019 mole) of methyl 2-isocyanatobenzoate and 50 ml. of benzene. The mixture was refluxed for 4 hours and the solvent was then evaporated on a Rinco evaporator. The solid residue was dissolved in a refluxing mixture of 30 ml. of hexane and ml. of benzene. On cooling, the product crystallized giving 4.80 grams (88.4%) of a light tan solid; M.P. 12ll23.5 C. After recrystallization the product melt at 121.5 122.5 C.

The following are among the many other compounds of the present invention which may be prepared according to the above-described procedures.

2-chloro-2-propenyl 2-(w,w-diethyleneoxyuramido) benzoate, M.P. 93 94 C.

2-chloroethyl 2-(w,w-diethyleneoxyuramido)benzoate,

M.P. 155.5-156.5 C.

5,13,;8-trifluoroethyl 2-(w,w-diethyleneoxyuramido)benzoate, M.P. 147.5 -l48 C.

l-methyl-Z-propenyl 2-(w,w-diethyleneoxyuramido) benzoate, M.P. 71-74 C.

2-propynyl 1-(w,w-diethyleneoxyuramido)benzoate, M.P.

phenyl 2-(w,w-diethyleneoxyuramido)benzoate, M.P.

2-butenyl 2-(w,w-diethyleneoxyuramido)benzoate, M.P.

tert.-butyl 2-(w,w-diethyleneoxyuramido)benzoate, M.P.

n-hexyl 2-(w,w-diethyleneoxyuramido)benzoate, M.P.

isobutyl 2-(w,w-diethyleneoxyuramido)benzoate, M.P.

2,4-dichlorophenyl 2-(w,w-diethyleneoxyuramido)benzoate, M.P. l57-l61.5 C.

2,2,2-trichloroethyl 2-(w,w-diethylenethiouramido)benzoate, M.P. l61-162 C.

2-chloroethyl 2-(w,w-diethylenethiouramido)benzoate,

M.P. 100101 C. I

allyl 2-(w,w-diethylenethiouramido)benzoate, M.P. 79.5

The uramidobenzoates of this-invention are useful as herbicides and are especially useful for controlling wild oats (Avena fatua). Wild oats present a serious weed problem in crops such as barley, soybeans, wheat, sugar beets, flax, and safllower. Many of the compounds of this invention can be applied to wild oats infesting these crops and will killpr suppress the growth of the wild oats without serious injury to the crop plants. Compounds which are presently preferred for controlling wild oats in the presence of desirable crops are the esters of 2-(w,w-diethyleneoxyuramido)benzoic acid in which the ester group is a primary alkyl of ,1 to about 3 carbon atoms. Thus, the presently preferred compounds are methyl 2-(w,w-diethyleneoxyuramido)benzoate, ethyl 2-(w,w-diethyleneoxyuramido)benzoate and n-propyl 2-(m,w-diethyleneoxyuramido)benzoate. These esters will give excellent control of wild oats in the presence of the crops in which wild oats are generally a serious problem, e.g., wheat, barley, alfalfa, and sugar beets. Yet, the corresponding free acid andits sodium salt are not selective in these applications. Surprisingly, application of the free acid to areas containing wild oats in the presence of the crops results in substantial injury and kill of the crops at rates necessary to control the wild oats.

The compounds are effective for controlling weeds such as wild oats by application as either a pre-emergen-ce or post-emergence treatment, that is, they can be used to kill or suppress the growth of growing plants or they can be used to prevent or suppress the emergence of seedlingplants. Thus, the compounds can be used to control the growth of wild oats by applying an effective amount of uramidobenzoate to the locus of the wild oats, that is the foliage of the growing plants or soil in which the plants are growing or will grow.

An application rate in the range of from about 0.25 to about lbs. of one or more of the active compounds per acre is generally an effective amount, although greater or lesser amounts can be used if desired. When used as a pre-emergence treatment, the presently preferred rate is in the range of from about 2 to about 20 lbs. per acre and when used as a post-emergence treatment a preferred application rate is in the range of from about 1 to about 15 lbs. per acre. At the higher rates of application the wild oat plants are killed but at lower rates the growth of wild oats is suppressed, allowing the crop to overtake the weeds and effectively crowd them out.

Also it has been noted that at the lower rates, although the wild oat plants are not killed, the amount of seeds set by the plants is reduced substantially, therefore providing a substantial benefit to the farmer in that his cereal crop is not contaminated with undesirable wild oat seeds.

The following examples illustrate the use of typical compounds of this invention for killing wild oats.

EXAMPLE X EXAMPLES XI-XVH Greenhouse pots planted to wild oats and barley were sprayed with methanol-dioxane solutions of several uramidobenzoates of this invention. The compounds were sprayed onto the soil in the pots immediately after planting at a rate of 2.5 pounds of uramidobenzoate per acre. Thirty days after treatment, the pots were rated for herbicidal activity on a 0:10 basis in which 0=no effect; 6=stunting with some kill and l0=all plants dead. The following results were obtained:

Herbicidal rating Wild Compound oats Barley XI n-Propyl 2- (w,w-diethylene-oxyuramldo) 9 nzoate. XII Ethyl 2-(w,w-dlethyleneoxy-uramido) 9+ benzoate. XIII- Methyl 2-(w,w-diethyleneoxy-thlouramldo) benzoate. XIV Allylg-(w,w-dlethyleneoxy-uramldo)ben- XV.-." Propynyl 2-(w,w-dlethylene-0Xyuramld0) benzoate.

XVI.-- 2-chloroethyl 2-(w,w-dlethylene-oxyuramido)benzoate.

XVII-.. Phenyl 2-(w,w-dlethyleneoxy-uramldo) benzoate.

OOOOOOO Since a relatively small amount of one or more of the active uramidobenzoates should be uniformly distributed over the area to be treated, the compounds preferably are formulated with conventional herbicide carrier, either liquid or solid. Thus, the compounds can be impregnated on or admixed with a puverulent solid carrier such as lime, talc, clay, bentonite, calcium chloride, vermiculite, calcium carbonate, and the like. Alternatively, the compounds can be dissolved or suspended in a liquid carrier such as water, kerosene, alcohols, Diesel oil, xylene, benzene, glycols, and the like. A surfactant preferably is included to aid in dispersion, emulsification and coverage. The surfactant can be ionic or nonionic, and may be liquid or a solid. The use of the term surfactant herein is intended to include such compounds commonly referred to as wetting agents, dispensing agents and emulsifying agents. Typical surfactants include the alkylarylsulfonates, the fatty alcohol sulfates, sodium salt of naphthalenesulfonic acid, alkyaryl polyether alcohols, long chain quaternary ammonium compounds, sodium salts of petroleum-derived al kylsulfonic acids, polyoxyethylenesorbitan monolaurate, and the like. These dispersing and wetting agents are sold under numerous trademarks and may either be pure compounds, mixtures of compounds of the same general group, or they may be mixtures of compounds of different classes. Surfactants can also be included in compositions containing a solid inert carrier.

Concentrated compositions containing the active agent which can be subsequently diluted, as with water, to the desired concentration for application to plants and soil are also provided. The advantages of such concentrates are that they are prepared by the manufacturer in a form such that the user need only mix them with a locally available carrier, preferably water, thereby keeping shipping costs to a minimum while providing a product which can be used with a minimum of equipment and effort. Such concentrates may contain from about to about 99 percent by weight of one or more of the active uramidobenzoates with a carrier or diluent, which may be a solid or liquid. Liquid carriers which are miscible with the H active agent or other liquids in which the compound may be suspended or dispersed may be used. A surfactant is also generally included to facilitate such dilution or dispersion in water. However, the surfactant itself maycomprise the carrier in such concentrates.

The herbicidal compositions can include other beneficial adjuvants, such as humectants, oils and contact agents. Also other herbicides, such as the chlorophenoxyacetic acids and haloalkanoic acids can be included in the formulation.

The following examples are presented to illustrate the preparation of suitable herbicidal compositions of this invention.

EXAMPLE XVIII Percent Methyl 2-(w,w-diethyleneoxyuramido)benzoate (powdered) Granular clay 95 A granular formulation can be prepared by dry blending the above constituents until uniformly mixed in a rotary mixer. A fine spray of water is sprayed onto the mixture, while tumbling to adhere the compound to the clay. The material is then air dried while tumbling to give a granular formulation which can be applied to the soil or vegetation by hand or by a mechanical spreader.

EXAMPLE XIX Percent n-Butyl 2-(w,w-diethyleneoxyuramido)benzoate 8S Bentonite clay 14 Sodium lauryl sulfate surfactant 1 A wettable powder formulation can be prepared by micronizing the uramidobenzoate and mixing uniformly with powdered bentonite clay and powdered sodium lauryl sulfate. The Wettable powder can be added to water or hydrocarbon oil and mechanically agitated to insure a uniform dispersion which can be sprayed with conventional equipment on soil or vegetation.

EXAMPLE XX Percent Ethyl 2-(w,w-diethyleneoxyuramido)benzoate 15 Polyoxyethylenesorbitan monolaurate 2 Isopropanol Xylene 53 The uramidobenzoate is dissolved in a mixture of isopropanol and xylene to form a concentrated solution. The emulsifying agent is then dissolved and a liquid formulation of an emulsifiable concentrate is obtained. The emulsifiable concentrate can be added to water to dilute to a desired concentration, and then be sprayed with conventional equipment on soil or vegetation.

Various changes and modifications of the invention can be made and, to the extent that such variations incorporate the spirit of this invention, they are intended to be included within the scope of the appended claims.

What is claimed is:

1. A compound of the formula COOR where R is selected from the group consisting of methyl, ethyl, n-propyl, allyl, propynyl, 2-chloroethyl, and phenyl and X is selected from the group consisting of oxygen and sulfur.

2. A compound according to claim 1 wherein X is sulfur.

3. A compound according to claim 2 wherein R is methyl.

4. A compound according to claim 1 wherein X is oxygen.

5. A compound according to claim 4 wherein R is n-propyl.

6. A compound according to claim 4 wherein R is ethyl.

7. A compound according to claim 4 wherein R is methyl.

8. A compound according to claim 4 wherein R is allyl.

9. A compound according to claim 4 wherein R is propynyl.

10. A compound according to claim 4 wherein R is 2-chloroethyl. A

11. A compound according to claim 4 wherein R is phenyl.

References Cited UNITED STATES PATENTS 3,404,975 10/ 1968 Wilson et a1 260247.1 2,642,428 6/ 1953 Weinlard et a1 260247.l 2,409,829 10/1946 Boon 260-553 OTHER REFERENCES Staiger et al., Journal of Organic Chemistry, Vol. 18, pp. 1427-1439 (1953).

ALEX MAZEL, Primary Examiner J. TOVAR, Assistant Examiner US. Cl. X.R. 

